WO 2005/002577 (F. Hoffmann-La Roche AG), WO 2006/013050 (F. Hoffmann-La Roche AG) and WO 2007/028654 (SmithKline Beecham Corporation) describe series of pyridine derivatives which are claimed to be dual NK1/NK3 antagonists for treating schizophrenia. WO 02/16324 (F. Hoffmann-La Roche AG) describes 4-phenyl pyridine derivatives as NK1 receptor antagonists.